生物技术在植物性杀虫剂研究开发中的应用

植物性杀虫剂是与环境有较高和谐度的害虫控制制，但研究开发进程缓慢。生物技术将是二十一世纪的主导技术，是解决人类面临的诸多问题的有力武器。利用基因工程技术对杀虫植物进行遗传改良以提高植物性杀虫剂的含量。应用植物细胞培养技术对高效杀虫植物加大繁殖力度以及对杀虫植物进行器官、细胞大规律发酵培养，从而解决植物性杀虫剂的来源问题。利用昆虫细胞培养技术可以加快有效杀虫植物的初筛和 植物性杀虫剂的抗性预报等。可见，生物技术与植物性杀虫剂研究的有机结合，必将使这门学科更好、更快地向前发展。     

黄瓜和葡萄霜霉病菌对不同内吸杀菌剂的交互抗药性

为了确定甲霜胺、乙磷铝与恶唑烷酮、霜脲氰、安克和硫代磷酰胺酯之间的交抗型,在叶盘上共测试了黄瓜霜霉(PC)和葡萄霜霉(PV)的27个分离系对6种内吸杀菌剂的抗药水平,结果证实了在两种目标真菌上甲霜胺和乙磷铝之间的非交抗关系,甲霜胺和恶唑烷酮之间的正交互抗药性,在PC上甲霜胺和霜脲氰之间的非交抗关系。试验还表明在PC上甲霜胺和安克之间以及乙磷铝和霜脲氰之间的非交抗关系,在PV上甲霜胺和乙磷铝与硫代磷酰胺酯之间的非交抗关系。此外,试验发现了霜脲氰和安克在叶盘上对抗甲霜胺分离系具有很高的杀菌活性。     

Secretion of Natural and Synthetic Toxic Compounds from Filamentous Fungi by Membrane Transporters of the ATP-binding Cassette and Major Facilitator Superfamily

This review provides an overview of members of the ATP-binding cassette (ABC) and major facilitator superfamily (MFS) of transporters identified in filamentous fungi. The most common function of these membrane proteins is to provide protection against natural toxic compounds present in the environment of fungi, such as antibiotics produced by other microorganisms. In plant pathogenic fungi, these transporters can also be an important determinant of virulence on host plants by providing protection against plant defence compounds or mediating the secretion of host-specific toxins. Furthermore, they play a critical role in determining base-line sensitivity to fungicides and other antimycotic agents. Overexpression of some of these transporters can lead to the development of resistance to chemically-unrelated compounds, a phenomenon described as multidrug resistance (MDR). This has been observed in a variety of organisms and can impose a serious threat to the effective control of pathogenic fungi.     

十种常用农药与球孢白僵菌的生物学相容性

球孢白僵菌孢子粉与10种常用农药相容性的测定结果显示,随着孢子浓度上升,所试农药对孢子的抑制作用均有不同程度的增强。在1/10田间常规使用浓度下,百菌清和代森锰锌均能抑制或杀死孢子(萌发率<1％)。除阿维菌素外,所有杀虫剂均与白僵菌孢子相容,在常规使用浓度的10倍稀释液中孢子萌发率达90％以上。吡虫啉、蚜虱灵、灭多威和氟虫腈与孢子的相容性最好,其中吡虫啉和蚜虱灵对孢子萌发率的影响不明显随药剂浓度的变化而变化,即使在田间常规使用浓度下孢子萌发率也在95％以上,而阿维菌素与白僵菌的相容性极差。因此,应用白僵菌制剂防治害虫,选择生物学相容性好的农药以低剂量与白僵菌制剂混用,既可使菌剂增效,又可大幅度降低化学药剂用量。     

植物杀虫剂苦皮藤素对柑橘潜叶蛾控制效果的研究

用植物性杀虫剂苦皮藤素Ⅳ(KPT乳油)有效成分30、15mg/kg防治柑橘潜叶蛾,采用离体叶片浸叶法处理5s,3d后,幼虫校正虫口减退率分别为89.63%、63.02%;枝梢浸液法处理5s,5d后,潜道伸长度校正抑制率分别为76.12%和41.51%;10d后,对秋梢的相对保叶效果分别为69.34%和52.29%。结果表明,采用KPT乳油有效成分30mg/kg对柑橘潜叶蛾有较好的控制作用,对柑橘秋梢有良好的保护效果。     

An inhibitor of polyamine biosynthesis — Difluoromethylornithine — and the polyamine spermidine for the control of gray mold(Botrytis Cinerea)

Difluoromethylornithine (DFMO) — an inhibitor of polyamine biosynthesis, and the polyamine spermidine (Spd) reduced gray mold of tomato, pepper, eggplant, bean andSenecio sp. leaves, and of rose petals by 37–88% when applied at 0.1–1.0 mM each. Higher doses did not result in better control. The disease was also reduced significantly on tomato fruits by 1.0 inM DFMO and by 0.1–1.0 mM Spd, and on cucumber fruits by 0.1–1.0 mM of both compounds, but not on grape berries. The combination of 0.2 mM DFMO with 1.0 mM Spd controlled gray mold ofSenecio sp. and tomato leaves additively better than either treatment alone, whereas this effect was not observed in leaves of lettuce and pepper. Ethylene production was reduced significantly by Spd applied to leaves of tomato and pepper, but not by DFMO. Linear growth and germination of the fungus were affected by lower concentrations of DFMO (ED50 0.12–0.97 and 1.4, respectively) as compared with Spd. Spermidine and DFMO controlled white mold(Sclerotinia sclerotiorum) as effectively as did the fungicide benomyl. Contribution from the Agricultural Research Organization. No. 3195-E, 1991 series.     

中国木薯褐斑病发病规律调查及田间防治药效试验

褐斑病是世界木薯种植中的常见病害,也是危害中国木薯的重要病害。在前期工作基础上,2011—2018年,笔者们对中国木薯主栽区开展了褐斑病的普查及发生规律研究工作。结果表明,褐斑病在中国木薯主要种植区域均有发生,部分地区发病严重,主栽品种均不具备抗病性。2个地点3个木薯品种的3年系统病情调查结果表明,病害通常在木薯生长中期发生,随后逐渐加重,中后期流行为害。田间试验结果表明,咪鲜胺、多菌灵、丙环唑、保叶清等杀菌剂对褐斑病的危害有较好的减轻作用,建议在生产中推广应用。     

Long‐term effects of mulching,traditional cutting and no management on plant species composition of improved upland grassland in the Czech Republic

A shortage of available livestock for utilizing grassland biomass in Central Europe is challenging for the management of both semi‐natural grasslands and previously intensified (limed, fertilized and reseeded) upland grasslands. An alternative method of grassland management is mulching, in which aboveground biomass is cut, crushed and subsequently spread on the surface. This paper reports on an experiment to compare three different mulching frequencies (one, two and three times per year) with an unmanaged treatment and traditional management of two cuts per year (control) on a previously improved upland meadow. Plant species composition was monitored over 13 years. Traditional management of two cuts with biomass removal was the most suitable method for maintaining plant species richness and diversity, and both were reduced significantly in the once‐mulched and especially in the unmanaged treatment. Tall dicotyledonous weeds such as Urtica dioica, Cirsium arvense and Aegopodium podagraria were promoted by the unmanaged treatment and by mulching once a year. Higher frequency of defoliation had positive effects on the spread of short forbs such as Taraxacum spp., Plantago lanceolata and Trifolium repens. After eight years, there were changes in sward structure in the unmanaged and mulched‐once‐a‐year treatments, with increase in the tall/short species ratio. In conclusion, repeated mulching cannot substitute fully for traditional two‐cut management in improved upland meadows without decreasing plant species richness and diversity, and changing the sward structure. Although mulching once a year may prevent invasion by shrubs and trees, it also supports the spread of weedy species similar to no management.     

7 种杀菌剂对菌草食用菌 4 种病原真菌的室内毒力测定

为筛选有效防止菌草食用菌病原真菌的药剂,本研究选用 7 种杀菌剂对菌草食用菌 4 种病原真菌进行室内毒力测定。采用菌落直径法对 4 种病原真菌进行室内毒力测定,并计算毒力回归方程。7 种供试杀菌剂对菌草食用菌 4 种病原真菌的作用效果中,百菌清对哈茨木霉的抑制作用最好,EC50 值最小为 0.291 4 mg/L;多菌灵对蜡孔菌和侧耳木霉的抑制作用最好,EC50 值最小分别为 0.257 mg/L 和 1.030 4 mg/L;精甲霜?锰锌对赭曲霉的抑制作用最好,EC50 值最小为 9.233 4 mg/L。百菌清、咪鲜胺、多菌灵和精甲霜?锰锌对 4 种病原真菌均具有较好的抑制作用,建议生产上将这 4 种药剂轮换使用,以有效控制菌草食用菌病害。     

Impact of foliar nickel application on urease activity,antioxidant metabolism and control of powdery mildew (Microsphaera diffusa) in soybean plants

Nickel (Ni) is a cofactor for urease, an enzyme that breaks down urea into ammonia and carbon dioxide. This study aimed to evaluate the physiological impact of Ni on urea, antioxidant metabolism and powdery mildew severity in soybean plants. Seven levels of Ni (0, 10, 20, 40, 60, 80 and 100 g ha^?1) alone or combined with the fungicides fluxapyroxad and pyraclostrobin were applied to soybean plants. The total Ni concentration ranged from 3.8 to 38.0 mg kg^?1 in leaves and 3.0 to 18.0 mg kg^?1 in seeds. A strong correlation was observed between Ni concentration in the leaves and seeds, indicating translocation of Ni from leaves to seeds. Application of Ni above 60 g ha^?1 increased lipid peroxidation in the leaf tissues, indicative of oxidative stress. Application of 40 g ha^?1 Ni combined with 300 mL ha^?1 of fungicide reduced powdery mildew severity by up to 99%. Superoxide dismutase, catalase, peroxidase and urease enzyme activity were greatest under these conditions. Urea concentration decreased in response to Ni application. Urease activity in soybean leaves showed a negative correlation with powdery mildew severity. The leaf Ni concentration showed a positive correlation with the urease and a negative correlation with powdery mildew severity. The results of this study suggest that urease is a key enzyme regulated by Ni and has a role in host defence against powdery mildew by stimulating antioxidant metabolism in soybean plants.